Question

20. A rectangular plot of land has a perimeterthat does not exceed 36.4 meters. If thelength of the plot is 3 times the width, whatis the length of the rectangular plot?

Answer 1

ANSWER

The length does not exceed 13.65 meters.

EXPLANATION

Let the width of the plot of land be x.

This means that the length of the plot of land is:

$\begin{gathered} 3\cdot x \\ \Rightarrow3x \end{gathered}$

The plot of land is rectangular. The perimeter of a rectangle is given as:

$P=2(l+w)$

The perimeter of the land does not exceed 36.4 meters, which means that:

$P\le36.4$

This implies that:

$\begin{gathered} 2(l+w)\le36.4 \\ \Rightarrow2(3x+x)\le36.4 \\ \Rightarrow2(4x)\le36.4 \\ 8x\le36.4 \end{gathered}$

Hence, we can solve for x:

$\begin{gathered} \Rightarrow x\le\frac{36.4}{8} \\ x\le4.55\text{ meters} \end{gathered}$

Recall that length is:

$l=3\cdot x$

Therefore, the length of the plot of land has the values:

$\begin{gathered} l\le3\cdot4.55 \\ l\le13.65\text{ meters} \end{gathered}$

In other words, the length does not exceed 13.65 meters.